To be cost efficient in a high production system, such as in stamping, molding, machining, and the like, it is requisite that tool or fixture exchange time be minimal so as to hold to a minimum, or eliminate, the system's down-time. This is especially true in a molding system where the physical and chemical state of the materials worked on present additional down-time problems.
Operations involving the movement of fixtures of substantial size and/or weight are typically cumbersome and time-consuming, especially when the fixtures must be secured to a work surface after placement or repositioning thereon. Exact positioning of the fixture is often critical in achieving the desired results from the fixture and can be difficult to achieve with sizable, heavy fixtures. Further, the removal of such sizable fixtures involves laborious, time-consuming efforts to unsecure and remove the fixture from the work surface. The effort required to move such fixtures results in reduction of the rate of operations, increased labor expenses, and decreased flexibility in scheduling operations requiring different fixtures.
In the field of molding, e.g., injection molding and thermoforming, various sizes of molds are used to produce different products. The commercially used molds are typically quite heavy and cumbersome to move. The mount plates used to trim the products resulting from the thermoforming differ for each product and likewise are often of substantial size and/or weight. Most commercial operations routinely involve the production of a variety of molded products to meet customer requests. The amount of the product varies and the molds are changed according to the amount required of a particular product. The diversification of products as well as varying customer requests often requires frequent change of the molds or dies used in molding and associated operations. Further, the molds or dies must often be inspected and repaired or replaced. The removal and insertion of the molds or dies has typically involved laborious and time-consuming manipulation of various service fittings and the realignment of the mold or die to resume operations. In any high production operation, the down-time accompanying the change of molds or dies and the associated labor costs must be minimized to maintain the desired productivity. Therefore, a system which contains means for the quick change of a fixture such as a mold or a die in which the fixture can be quickly and securely fastened or released from a work surface is desirable.
Prior attempts to effect such quick change involve modification of guides for transfer, centering means and quick-lock and release clamps; see for instance each of the U.S. Pat. Nos.:
2,940,384 June 16, 1960 Manschuer et al. PA1 4,058,885 Nov. 22, 1977 Raymond A. Bergman PA1 4,354,796 Oct. 19, 1982 Raymond A. Bergman PA1 4,472,127 Sept. 18, 1984 Cyriax et al. PA1 4,555,228 Nov. 26, 1985 Nishiike et al.
It is an object of the invention to provide fixture or tool quick-change means having clamping means of a quick-release/lock type that uniquely associate with guide slots through which studs affixed to a fixture or tool translate.
It is another object of the invention to provide novel clamping means of a quick-release/lock type that uniquely associate with guide slots through which fixture or tool clamp studs translate.
It is a further object of the invention to provide an improved downstream clamp bar that is adjustably mounted for translation in slots of a platen and cooling plate to accommodate mold size.
Yet another object of the invention is to provide improved means for facilitating fixture or tool exchange which are relatively inexpensive to manufacture and uncomplicated with regard to assembly and use.